hdu 1247 Hat’s Words 字典树

来源：互联网发布：多表查询的sql语句编辑：程序博客网时间：2024/05/21 22:58

有几个地方要注意

1.分割字符串的细节

2.可能需要按字母表排序

3.搜索字典树的时候不要搜成了前缀，注意是一个字符串的终结

传送门：http://acm.hdu.edu.cn/showproblem.php?pid=1247

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <algorithm>#define maxn 30using namespace std;char a[50005][205];char ans[50005][205];struct Trie{    Trie * next[maxn];    int v;};Trie * root;int cmp(const void * a1,const void * a2){    char * p1 = (char *)a1;     char * p2 = (char *)a2;    return strcmp(p1,p2); }void Init_Trie(){    root = (Trie *)malloc(sizeof(Trie));    for(int i=0;i<maxn;i++){        root -> next[i] = NULL;    }}void Add_Trie(char * str){    Trie * p = root , * q;    for(int i=0;str[i]!='\0';i++){        int id = str[i] - 'a';        if(p->next[id]==NULL){            q = (Trie *)malloc(sizeof(Trie));            q -> v = 0;            for(int j=0;j<maxn;j++){                q -> next[j] = NULL;            }            p -> next[id] = q;            p = p -> next[id];        }        else {            //p -> next[id]->v++; //记录有某个共同前缀的单词数量            p = p -> next[id];        }    }    p -> v = 1;}int Search_Trie(char * str){    Trie * p = root;    for(int i=0;str[i]!='\0';i++){        int id = str[i] - 'a';        p = p -> next[id];        if(p==NULL){            return 0;        }    }    return p->v;}void Del_Trie(Trie * p){    for(int i=0;i<maxn;i++){        if(p->next[i])Del_Trie(p->next[i]);    }    free(p);}void Input(){    Init_Trie();    int i = 0;    while(~scanf("%s",a[i++])){        Add_Trie(a[i-1]);    }    int k,kk = 0;    for(int j=0;j<i;j++){        int mark = 0;        for(k=1;k<strlen(a[j]);k++){            char tempa[205];            char tempb[205];            int k1;            for(k1=0;k1<k;k1++){                tempa[k1] = a[j][k1];            }            tempa[k1] ='\0';            for(k1=k;k1<strlen(a[j]);k1++){                tempb[k1-k] = a[j][k1];            }            tempb[k1-k] = '\0';            if(Search_Trie(tempa)&&Search_Trie(tempb)){                mark = 1;                break;            }        }        if(mark){            for(k=0;k<strlen(a[j]);k++){                ans[kk][k] = a[j][k];             }            ans[kk][k] = '\0';            kk++;        }    }    qsort(ans,kk,sizeof(ans[0]),cmp);    for(int i=0;i<kk;i++){        puts(ans[i]);    }    Del_Trie(root);}void File(){    freopen("a.in","r",stdin);    freopen("a.out","w",stdout);}int main(void){    //File();    Input();    return 0;}

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